Venison wellington can be made in advance and served as the centerpiece for a dinner party.
Place a large frying pan over a medium heat. Rub the venison all over with olive oil and season well with salt and freshly ground black pepper. Place the venison in the pan and seal on all sides. Remove from the pan and set aside to cool.
For the duxelles, add the butter to the same frying pan. Once hot and foaming, turn the heat down and fry the shallots for 2-3 minutes, or until softened. Add the mushrooms and thyme and cook for a further 6-8 minutes.
Pour in the port and continue to cook until it has almost completely reduced. Remove the pan from the heat and allow the duxelle mixture to cool.
Lay a large piece of clingfilm out on a work surface. Lay the slices of prosciutto out on the cling film, overlapping each other. Spread the cooled duxelles mixture over the prosciutto slices.
Spread the pâté over the venison and sit it in the middle of the duxelle mixture. Use the clingfilm to wrap the proscuitto around the venison. Chill in the fridge for at least 30 minutes.
Preheat the oven to 200C/400F/Gas 6.
Cut two pieces of puff pastry approximately 5cm/2in longer and wider than the wrapped piece of venison.
Place one piece of pastry on a chopping board. Remove the venison from the fridge, carefully remove the clingfilm and place it in the middle of the pastry.
Brush egg wash all over the venison and press the second piece of pastry on top. Seal it down the sides of the meat and bring up the bottom piece of pastry to seal the wellington together. Trim off any excess pastry. Place in the oven for 15 minutes.
Turn the oven down to 150C/300F/Gas 2 and cook for a further 10 minutes.
Remove from the oven and allow to rest before carving into slices.
